Switch and fuse mechanism



June I l, 1935.

E. e. JOHANSSON 2,004,327 SWITCH AND FUSE MECHANISM Original Filed Dec. 26, 1950 s Sheets-Sheet i 470%??? 1%? mama,

ZIWWMM June 11, 1935. E G JOHANSSON 2,004,327

SWITCH AND FUSE MECHANISM Original Filed Dec, 26, 1950 3 Sheets-Sheet 2 June 11, 1935. G JOHANSSON 2,004,327

SWITCH AND FUSE MECHANISM Original Filed Dec. 26, 1930 3 Sheets-Sheet 3 Patented June 11, 1935 UNITED STATES PATENT OFFICE SWITCH AND FUSE MECHANISM Waltham, chusetts Mass, a

corporation of Massa- Application December 26, 1930, Serial No. 504,762 Renewed April 13, 1935 13 Claims.

When enclosed fuse switches are employed it is important, particularly when operation of the switch is liable to be effected by persons not highly skilled in the handling of electrical mech- 5 anisms, that the fuses shall be accessible for inspection and replacement but only when they are disconnected from live conductors and that the conductors be not readily accessible to unauthorized persons.

In order to protect the live conductors from ready access, barrier means may be positioned between them and the accessible fuse or fuse portion. This means may be in the nature of a relatively small protecting enclosure or receptacle wherein the fuse may be made accessible. This enclosure or receptacle may be provided with a suitable cover, and some sort of interlock between means for securing the cover shut and the switch actuating means may be provided, whereby the cover closes off the receptacle and prevents access to the fuse when the switch is closed and the fuse terminal may be alive, but which permits opening of the cover when the switch is open. While the fuse should not be accessible to unauthorized persons except when disconnected from live terminals, it should be possible for an authorized person to obtain accessto the fuse, switch and terminals when the switch is either open or closed, so that the switch may be actuated while accessible so that proper inspection may be made of its operating parts. It is also important that when a fuse is carrying current it be positioned where it may radiate heat freely, as it is found that if it be enclosed within a relatively small chamber where such radiation is limited it becomes hot after a period of service and is liable to blow after a time under less than rated current flow.

Oneobject of the present invention is to retain the advantage incident to the fuse being in the relatively large enclosure containing the switch during service, and to render the fuse normally accessible only when disconnected from live parts, but without requiring movement of the fuse when the switch is actuated. In order to render the fuse accessible for inspection or for removal or replacement, means are provided,

according to this invention, by which, when theswitch is in open position the fuse cover may be opened to permit inspection of the fuse, and whereby the fuse may be projected partly through the barrier which hinders access to conductors which may be alive, and without the use of tools, where it may be grasped and withdrawn.

A further object of the invention is to provide (01. ZOO-50) a simple and efiective mechanism for insuring opening of the switch before the fuse may be made normally accessible, either for inspection or removal, and for insuring locking of the fuse against normal access before the switch may be closed; and to produce such a mechanism which will clearly indicate each of its operative conditions and the action necessary to change it from one to the other.

Further objects and advantageous features will appear from a more complete description of an embodiment of the invention disclosed in the accompanying drawings in which Figure 1 is a top plan of an enclosed fused switch, the switch being in open position.

Figure 2 is a View similar to Figure 1 but with the main cover removed.

Figure 3 is a section on line 3-3 of Figure 1, the switch actuating handle being shown by dotted lines in switch-closed position.

Figure 4 is a, view similar to a portion of Figure 3, but showing the supplemental cover open.

Figure 5 is a perspective of the supplemental cover-securing elemnt.

Figure 6 is a side elevation showing the switch actuating handle in full lines in switch-open position and in dotted lines in switch-closed position.

Figure 7 is a detail section on line '|-1 of Figure 3.

Figure 8 is a view similar to Figure '7 but showing the fuse in partly ejected position.

Figures 9 and 10 are detail sections on the correspondingly numbered section lines of Figures 7 and 8, respectively.

Figure 11 is a detail section on line lI.-l I Figure 3.

Figures 12 and 13 are views similar to Figure 11 but showing certain of the parts in different positions.

Figure 14 is a detail section on line l4l4 of Figure 12.

Figure 15 is a wiring diagram showing meter. connections for a three-wire A. C. circuit with a grounded neutral.

Figure 16 is a perspective of a switch and fuse block.

Figure 17 is a view similar to Figure 2, but showing a difierent arrangement of parts.

Figure 18 is a detail section on line l8--I8 of Figure'l'l.

Figure 19 is a wiring diagram for the arrangement shown in Figure 17.

Referring to these drawings, at I are shown insulating blocks which carry switch and fuse are jaws 6 spaced to receive therebetween the terminals 1 of a cartridge type fuse 8. If desired one or both of the fuse clips may have the outer edge portion of each of the jaws provided with a slit II), the material outwardly of the slit being bowed inwardly as shown at I I to form a stop to limit endwise movement of the fuse. This is of particular utility when the block I is so mounted in service that the fuse is in substantially a vertical position.

The block I is shown as provided with a slot I5 within which may ride a switch arm I6 .(see Figures l1, l2, l3 and 18). As shown this arm I6 is of generally sector shape and is formed of insulation, and is provided near its outer margin with a slot I8 through which is extended a conducting strip i9, the ends of which are bent against opposite faces of the arm I6 and may, if desired, have their extremities formed to engage in recesses 20 in these faces. This element t8-forms the movable contact member of the switch, which when the switch is in closed position, extends between and in electrical conductivity with the fixed terminals 2| and 22. One of these fixed conductors 2i may be in electrical connection with a fuse clip as 2 and the other may be connected to a terminal 23. The fuse clip 2 is likewise in electrical connection with a terminal" 245 The jaw 3 is shown as supported on a short conducting strip to which may be secured the strap conductor 26 leading through a link 21 to a terminal 28. The link 21 may be detached when desired for the purpose of meter testing in a. well understood manner.

The terminal 23 is partially surrounded'by an angular wall portion 36 of the block I which forms a barrier obstructing access thereto. Two of these blocks I with the switch terminals are shown as placed side by side and secured to the base "portion of an enclosing casing having side walls 36 and 3'! and end walls 38. While two of these blocks are shown, one or more might be employed, depending on the particular type of circuit being controlled, two being suitable for a three-wire circuit with a grounded neutral, in connection with which this invention will be more particularly described. It should be understood, however, that the number of blocks will depend on the type of circuit which is to be controlled. Between the two blocks are shown a barrier 40 of insulation.

The top of the casing or enclosure is formed by a'main cover hinged at one side as at 45 to the side wall 37 and having a marginal flange extending about the sides and ends of the en closure when the main cover is closed. This main cover is shown as provided with an opening which may be closed by means of a supplemental'cover 5| hinged to the main cover as at 52. Carried on the inside of the main cover about the opening 58, are inwardly projecting wall portions 53 supporting a base plate 5 1 of insulating material which forms with the wall portions 53, a shallow box portion which may be closed by the supplemental cover '55. Through the base member 54 are openings 55 positioned immediately above the fuse clips 2 and 3 and of such a size that a fuse may be inserted through each opening 55 into engagement with the clips or removed from the clips therethrough. The

base 54 forms a barrier which obstructs free access to the switch and the various conductors within the main enclosure but is positioned above the fuses 63 so that these fuses when in engagement with their clips are within the relatively large main enclosure wherein the switches are carried, but they may be inspected through the openings 55 while in operative position, when the door M is open.

Provision is made, in accordance with this invention, so that when desired, each fuse may be projected outwardly through its opening 50 sufficiently so that it may be grasped and removed without the use of tools. To this end one of the clips such as the clip 3 may be provided with fuse ejecting mechanism. As shown best in Fig- 7 to 10 this mechanism comprises a rod 65 journaled' in opposite jaw portions 6 and having between these jaw portions an offset portion 66 eccentrically disposed to the journals. When the fuse is in position. between the jaws this offset portion may rest upon the upper edge of an angle stop member ti? beneath the fuse, as shown best in Figure '7. Outwardly of one of the jaws 6 the rod 65 is bent to form a handle portion 58 which is preferablyenclosed with insulation as at it. This handle portion extends outwardly through a laterally extended portion II of the slot 55 into the shallow box portion back of the supplemental cover 55 where it may be grasped by the fingers. By pressing the handle 59 in the proper direction, as shown in Figure 8, the offset portion 68 is pressed against the fuse terminal '52 and by expressure onthe handlett this fuse ter-' minal may be forcibly ejected as shown best in Figures and so that it projects through the barrier 5: 1 where it can be grasped by the fingers sufficiently so that the entire fuse may be removed from between its clips.

The rod 55, as shown best in Figures 9 and 10, may be journalcd in the jaws 6 slightly below a portion iii of each, these portions l5 being spaced a distance less than where the rod 65 is journale'd, and the maximum width of the offset portion 66 may be greater than the normal spacing of the portions 75 so that as the handle 68 is turned these more widely spaced portions of the rod wedge in between the portions 75 and spread the jaws 5 thus tofacilitate ejection-of the fuse. The mounting of the fuses per se is not claimed herein but forms the subject matterof a divisionalapplication Serial No. 562,311, filed September 11, 1931, for Fuse mechanism i The switch'arms or sectors Iii in the blocks I may be fixed to a polygonal actuatingshaft Bil suitably journaled within the main casing, and an actuating handle by which this shaft may be turned is positioned outside of the casing as at iii to move in a plane substantially parallel" to the side wall 353 of the casing. Any suitable operative connection between the handle and the shaft may be employed. As shown, for example, in Figures 1 and 11 to 13, the handle BI is secured to a disk member 32 which is connected through a central pivot passing through the wall 35 to a disk 33 on the inner face of this side wall. This disk 83 has a pin G 3 projecting inwardly therefrom which rides in a slot I35 in a linkmember 86. This link member is pivoted on'the shaft 88 and is operatively connected thereto through a spring 8'! and stop portions 88 and '85 which cooperate with a stirrup til secured to the shaft 80. The stops 538 and 89 provide a slight lost motion connection within the range of which the spring 8? is tensioned so as to produce a quick break of the switch, the spring completing the motion quickly after positive actuation of the contact members sufiicient to permit their disengagement.

In order that the switch and fuses may be rendered accessible to authorized persons in any position of the switch, the main cover 45 is provided with any suitable means for sealing it in closed position, as, for example, the sliding bar 95 which may be projected through slots in the cover flange and the wall 36, whereupon a sealing wire may be placed through an opening 96 outwardly of the cover flange. Any other means may be provided, this per se forming no part of the present invention.

Means, however, is provided by which without breaking the seal and opening the main cover access may be had to the fuses only when the switch is in open position and by which the switch cannot be moved to closed position while the fuses are accessible. This means, as shown, comprises a plate element I00, shown detached in Figure 5, and which is provided with obliquely arranged slots IOI by which it may be slidably secured to the outside of the main cover 45 as by the rivets I02. This element I00, when in the position shown in Figure 1, has an edge portion I03 overlying the free edge I05 of the supplemental cover 5I remote from the hinges 52 and has a side portion I06 which overlies a side edge I01 of this supplemental cover, thus securing the supplemental cover against opening by means overlying angularly related edges of the supplemental cover for substantially theirentirelengths.

I The side portion I03 is shown as provided cengaged to facilitate opening when the element I00 is out of cover-securing position. The element I00 has a flange portion II5 which projects outwardly of the marginal flange of the main cover 45 and serves to stiffen this member I00. It also is preferably provided with an outwardly projecting flange IIS adjacent to one of the hinges 52. When the element I00 overlies the angularly related edges of the door 5I, its flange I I5 lies close against the main cover flange, permitting free motion of the handle 8| between switch closed and open position as may be desired. When the switch handle BI is in switch closed position, however, it projects across the path of motion of the element I00 for releasing the supplemental cover 5I, as shown in dotted lines in Figures 3 and 6, so that it is impossible to move the element I00 to release the supplemental cover 5I when the switch is closed. When the switch is open, however, the handle BI is in the full line position shown in Figures 3, 4 and 6, whereupon the element I00 can be moved outwardly in a direction oblique to the plane of the side wall 36, uncovering the edges of the supplemental cover 5!, but such motion brings the flange I I5 into the path of movement of the handle 8| from open switch position to closed switch position, thus preventing the closing of the switch when the element I00 is in supplemental cover-released position. A loop element I secured to the outer face of the sidewall 30 prevents the possibility of the operating handle 0| being sprung outwardly sufiiciently to clear the flange I I5. When the element I00 is in its supplemental cover-releasing position and this cover is open, in the position shown in Figure 3, the flange II6 on the member I00 lies outwardly of the edge of the supplemental cover, the cover thus preventing this member I00 from being moved to its supplemental cover-securing position as long as this supplemental cover is open.

In Figure 15 is shown a wiring diagram for the mechanism heretofore described, when used as a meter service box for a three-wire alternating current installation having a grounded neutral. The neutral both of the load and line is connected to the ground terminal I30 within the casing, the outside service lines being connected first through the switch terminal 22, the two switches, and then the fuses to the conductors and from these through the current coils I3I and I32 of the meter. At I33 is shown the potential coil of .the meter which is connected on the load sides of the switches. The blocks I, however, are quite capable of being reversed and associated as shown in Figure 15 so that the wiring may be arranged as shown in Figure 19. In this arrangement the load and line neutrals are grounded through the ground terminal I as before, but the outside service lines are connected first through the terminals I35 with the current coils I3I and I32 of the meter and then through the switches and then the fuses to the load. In this arrangement of the parts the direction of motion of the switch arm I0 is reversed to that shown in the arrangement of Figure 2 so that the connection between the shaft 80 and the actuating handle III is modified, the handle and shaft turning in the same direction rather than in opposite directions as is shown in Figure 2. The arm is connected directly with the shaft through lost motion which tensions the spring so that when the switch starts to open the spring snaps the movable terminal away from the stationary terminals. Otherwise the construction may be substantially the same.

From the foregoing description of certain embodiments of this invention, it should be evident to those skilled in the art that various changes and modifications might be made without departing from the spirit or scope of this invention as defined by the appended claims.

I claim:

1. In combination, a fuse, a switch in circuit with said fuse and movable between open and closed positions, an enclosure for said switch and fuse of large size with respect to said fuse and accessible for free radiation of heat therefrom and having a restricted passage through which said fuse may be passed for insertion or removal and bafliing access to said fuse when said fuse is within said enclosure, and means normally accessible only when said switch is open actuable to project a portion of said fuse outside of said enclosure to permit grasping and removing said fuse.

2. In combination, a fuse, a switch in circuit with said fuse and movable between open and closed positions, an enclosure for said switch and fuse of large size with respect to said fuse and accessible for free radiation of heat therefrom and having a restricted passage through which said fuse may be passed for insertion or removal and bafiiing access to said fuse when said fuse is within said enclosure, and means actuable while said switch is stationary to project a portion of said fuse outside of said enclosure to permit grasping and removing said fuse.

3. In combination, a fuse, a switch in circuit with said fuse and movable between open and closed positions, an enclosure for said switch and fuse of large size with respect to said fuse and accessible for free radiation-of heat therefrom and having a restricted passage through which said fuse may be passed for insertion or removal and baffling access to said fuse when said fuse is within said enclosure, and means actuable normally only when said switch is in open position to project a portion of said fuse outside of said enclosure to permit grasping and removing said fuse.

4. In combination, an enclosure, a switch and a fuse in circuit within said enclosure, said enclosure having a' wall member with an aperture through which said fuse may be inserted or removed and through which said fuse may be inspected, said aperture being'so restricted as to render said fuse inaccessible for manual removal when wholly within said enclosure, a support for said fuse within said enclosure spaced in wardly from said apertured wall to permit free circulation of air in said enclosure around said fuse, and means accessible only when said switch is open for ejecting a portion of said fuse through said aperture into position to be grasped by the fingers and make possible complete manual removal of said fuse from within said casing.

5. In combination, an enclosure, a switch and a fuse in circuit within said enclosure, said enclosure having a wall member provided with an opening through which said fuse may be inserted or removed and through which said fuse may be inspected, said opening being so restricted in size as to render said fuse inaccessible for manual removal therethroughwhen within said enclosure, a support for said fuse within said enclosure space from said wall member to permit free circulation of air within said enclosure around said fuse, a cover for said opening, means for normally-preventing opening of said cover while said switch is closed and for preventing closing of said switch while said cover is open, and means normally accessible only when said cover is open for projecting aportion of said fuse through said opening into position for said fuse to be grasped and removed fromv said enclosure.

6. In combination, an enclosure, a switch and a fuse in circuit within said enclosure, said enclosure having a wall member provided with an opening through which said fuse may be inserted or removed and through which said fuse may be inspected, said opening being so restricted in size as to render said fuse inaccessible for manual removal therethrough when within said enclosure, a support for said fuse within said enclosure spaced from said wall member to permit free circulation of air within said enclosure around said fuse, a cover for said opening, means normally accessible only when said switch is open actuable to project a portion of said fuse through said opening outside of said enclosure to permit grasping and removing said fuse, and means affording authorized access to said fuse irrespective of the position of said switch.

'7. In combination, an enclosure, a switch and a fuse in circuit within said enclosure, said enclosure having a wall member provided with an opening through which said fuse may be inserted or removed and through which said fuse may be inspected, said opening being so restricted in size as to render said fuse inaccessible for manual removal therethrough when within said enclosure, a support for said fuse within said enclosure spaced from said wall member to permit free circulation of air within said enclosure around said fuse, a cover for said opening. means actuable normally only when said switch is open to project a portion of said fuse through said opening outside of said enclosure to permit grasping and removing said fuse, and means affording authorized access to said fuse irrespective to the position of said switch.

8. In combination, a fuse, a switch and conductors in circuit with said fuse. a casing of large size with respect to said fuse enclosing said switch, fuse and conductors and having a main cover scalable against unauthorized opening, said main cover having an opening therethrough adjacent to said fuse, a barrier beneath said opening and having an opening through which said fuse may be visible for inspection, a support for said fuse within said casing spaced from said barrier to permit free circulation of air in said casing about said fuse, said barrier obstructing access to said switch and conductors, a supplemental cover carried by said main cover and when closed closing said cover opening, a switch actuating means projecting outside of said casing, and an element movable on said main cover and in one position holding said supplemental member closed, said actuating member when in switch-closed position obstructing and preventing movement of said element to release said supplemental cover and said element when in cover-closed position obstructing and preventing movement of said member to switch-closed position.

9. In combination, a fuse, a switch and conductors in circuit with said fuse, a casing of large size with respect to said fuse enclosing said switch, fuse and conductors and having a main cover scalable against unauthorized opening, said main cover having an opening therethrough adjacent to said fuse, a barrier beneath said opening and having an opening through which said fuse may be visible for inspection, a support for said fuse'within said casing spaced from said barrier to permit free circulation of air in said casing about said fuse, said barrier obstructing access to said switch and conductors, a supplemental cover carried by said main cover and when closed closing said cover opening, a switch actuating means projecting outside of said casing, an element movable on said main cover and in one position holding said supplemental member closed, said actuating member when in switchclosed position. obstructing and preventing movement of said element to release said supplemental cover, and said element when in cover-closed position obstructing and preventing movement of said member to switch-closed position, and an element normally accessible only when said supplemental cover is open and actuable to project a portion of said fuse through said barrier opening. sufficiently to permit said fuse to be grasped by the fingers and entirely removed.

10. In combination, a fuse, a switch, an enclosure for said fuse and switch having an opening through which access may be had to said fuse, a cover for said opening, a'switch actuating member outwardly of .said enclosure, and an element movably carried by said enclosure and in one position overlying angularly related edge portions of said cover for substantial distances and securing said cover closed and in another position freeing said cover and lying in the path of motion of said switch actuating member from switcheopen to switch-closed position, said member when in switch-closed position obstructing the movement of said element from door-securing to door-releasing positions.

11. In combination, an enclosure having a sealable main cover, a fuse and a switch Within said enclosure, a switch actuating means projecting outwardly of said enclosure and having a handle movable in a plane substantially parallel to a side wall of said enclosure, said main cover having an opening therethrough through which said fuse may be inspected while said main cover is closed, a supplemental cover for said opening hinged to said main cover, a slide carried by said main cover and movable at an angle oblique to said side wall in one position engaging over the free end of said supplemental cover and one side edge thereof and securing said supplemental cover closed and when out of engagement with said supplemental cover projecting beyond said side wall into the normal path of motion of said handle when being moved from switch open to closed positions, said handle when in closed switch position projecting across the plane of movement of said slide and preventing movement of said slide to supplemental cover-releasing position, said supplemental cover when open lying in the path of movement of said slide toward cover-securing position and preventing such movement.

12. In combination, a fuse, a switch in circuit with said fuse, a casing enclosing said switch and fuse, and having an opening through which said fuse may be inspected, a cover for closing said opening, a handle outside of said casing movable in a plane substantially parallel to one side of said casing for opening and closing said switch, an element cooperating with two angularly disposed sides of said cover for securing said cover closed, and means for mounting said element for movement oblique with respect to said plane from and to securing position.

13. In combination, a fuse, a switch in circuit with said fuse, a casing enclosing said switch and fuse, and having an opening through which said fuse may be inspected, a cover for closing said opening, a. handle outside of said casing movable in a plane substantially parallel to one side of said casing for opening and closing said switch, an element cooperating with two angularly disposed sides of said cover for securing said cover closed, and means for mounting said element for movement oblique with respect to said plane from and to securing position, said handle and elements having parts cooperating to insure said element being in said cover-securing position when said switch is in closed position.

ERNEST G. JOHANSSON. 

